U.S. patent application number 14/800283 was filed with the patent office on 2016-01-21 for devices and methods for intrahepatic shunts.
The applicant listed for this patent is VOLCANO CORPORATION. Invention is credited to Dino De Cicco, Jeremy Stigall, John Unser.
Application Number | 20160015422 14/800283 |
Document ID | / |
Family ID | 54015133 |
Filed Date | 2016-01-21 |
United States Patent
Application |
20160015422 |
Kind Code |
A1 |
De Cicco; Dino ; et
al. |
January 21, 2016 |
DEVICES AND METHODS FOR INTRAHEPATIC SHUNTS
Abstract
The invention provides methods and devices for treating liver
cirrhosis or portal hypertension by creating an intrahepatic shunt,
or new passage, from a portal vein of a patient to a hepatic vein
using a device with intravascular imaging capabilities and pressure
sensing capabilities or positioning mechanisms. The integration of
intravascular imaging aids in the precise placement of the shunt
and pressure measurement may verify successful shunt creation. An
apparatus may include a catheter with an extended body for
insertion into a hepatic vein of a patient, an intravascular
imaging device and a needle exit port on the distal portion of the
extended body, and a needle disposed within a lumen in the catheter
and configured to be pushed out of the exit port and extend away
from a side of the extended body, in which the needle includes a
pressure sensor.
Inventors: |
De Cicco; Dino; (San Diego,
CA) ; Stigall; Jeremy; (San Diego, CA) ;
Unser; John; (Temecula, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VOLCANO CORPORATION |
San Diego |
CA |
US |
|
|
Family ID: |
54015133 |
Appl. No.: |
14/800283 |
Filed: |
July 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62024520 |
Jul 15, 2014 |
|
|
|
Current U.S.
Class: |
600/439 ;
600/104; 600/464; 600/561 |
Current CPC
Class: |
A61B 2017/22069
20130101; A61B 2562/0247 20130101; A61B 8/461 20130101; A61B 17/11
20130101; A61B 2017/1107 20130101; A61F 2/07 20130101; A61B
17/06066 20130101; A61B 17/3478 20130101; A61B 8/12 20130101; A61B
2017/22054 20130101; A61B 8/0841 20130101; A61B 2090/064 20160201;
A61B 2017/00022 20130101; A61B 2017/1139 20130101; A61B 2017/22071
20130101; A61B 8/445 20130101; A61B 8/0891 20130101; A61B 2090/3784
20160201 |
International
Class: |
A61B 17/34 20060101
A61B017/34; A61B 8/08 20060101 A61B008/08; A61B 8/00 20060101
A61B008/00; A61B 8/12 20060101 A61B008/12 |
Claims
1. An apparatus for creating an intrahepatic portosystemic shunt,
the apparatus comprising: a catheter with an extended body
configured for insertion down a jugular vein into a hepatic vein of
a patient; an intravascular imaging device on a distal portion of
the extended body; a needle exit port on the distal portion of the
extended body; and a needle disposed within a lumen in the catheter
and configured to be pushed out of the exit port and extend away
from a side of the extended body ; and a pressure sensor disposed
on the needle.
2. The apparatus of claim 1, wherein the needle extends away from
the side of the extended body by a distance of at least 1 cm.
3. The apparatus of claim 2, wherein the needle comprises a shape
memory metal that assumes a curved shape as the needle exits the
exit port.
4. The apparatus of claim 3, wherein the needle comprises a lumen
extending therethrough, the lumen dimensioned to receive a
guidewire.
5. The apparatus of claim 3, wherein the intravascular imaging
device comprises an ultrasound transducer.
6. The apparatus of claim 5, wherein the needle is dimensioned to
extend from the exit port away from the side of the catheter body
through tissue and into a portal vein.
7. The apparatus of claim 6, wherein the needle comprises a sharp
tip configured to pierce through the tissue between the hepatic
vein and the portal vein thereby creating a portosystemic
shunt.
8. The apparatus of claim 7, wherein the IVUS transducer is
operable to produce an image of the portal vein when within the
hepatic vein.
9. The apparatus of claim 8, wherein a proximal end of the catheter
is attached to an imaging system comprising a processor and a
display, and wherein the image produced by the IVUS transducer is
viewable on the display.
10. The apparatus of claim 1, further comprising a positioning
mechanism operable to bias a portion of the extended body towards a
side of the first vessel.
11. The apparatus of claim 10, wherein the positioning mechanism
comprises a first balloon and a second balloon disposed in parallel
to one another along a length of the extended body.
12. The apparatus of claim 1, wherein the needle comprises a lumen
for delivering a treatment agent to the tissue.
13. An apparatus for creating an intrahepatic portosystemic shunt,
the apparatus comprising: a catheter with an extended body
configured for insertion down a jugular vein into a hepatic vein of
a patient; an intravascular imaging device on a distal portion of
the extended body; a needle exit port on the distal portion of the
extended body; a needle disposed within a lumen in the catheter and
configured to be pushed out of the exit port and extend away from a
side of the extended body; and a first balloon and a second balloon
disposed in parallel to one another along a length of the extended
body opposed to the needle exit port, wherein inflation of the
first balloon and the second balloon biases a portion of the
extended body towards a side of the hepatic vein.
14. The apparatus of claim 13, wherein the needle extends away from
the side of the extended body by a distance of at least 1 cm.
15. The apparatus of claim 14, wherein the needle comprises a shape
memory material that assumes a curved shape as the needle exits the
exit port.
16. The apparatus of claim 15, further comprising a pressure sensor
disposed on the needle.
17. The apparatus of claim 13, wherein the intravascular imaging
device comprises an ultrasound transducer operable to produce an
image of a portal vein when within the hepatic vein.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to, and the benefit of,
U.S. Provisional Application No. 62/024,520, filed Jul. 15, 2014,
which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to devices and methods for creating
intrahepatic shunts.
BACKGROUND
[0003] A person with cirrhosis of the liver may have bloody vomit
or stool. Untreated, cirrhosis can cause shock and death. Liver
cirrhosis--which can result from alcoholism, hepatitis, disease, or
unknown causes--is characterized by scar tissue and nodules in the
liver that lead to loss of liver function. Liver cirrhosis presents
resistance to blood flow through the portal venous system, causing
undue pressure, or portal hypertension. Effects of portal
hypertension include collateral blood flow that swells the vessels
around the esophagus. Swollen esophageal vessels, or varices, are
known to burst, resulting in variceal bleeding. After esophageal
varices have bled once, there is a high risk of bleeding again.
Bleeding varices can appear as bloody stool and vomit and variceal
bleeding can lead to shock and death. Thus, liver cirrhosis, portal
hypertension, and esophageal varices are associated with patient
mortality. In fact, twenty percent of cirrhotics with acute
variceal hemorrhage die within six weeks. See Loffroy, 2013,
Transjugular intrahepatic portosystemic shunt for the management of
acute variceal hemorrhage, World J Gastroent 19(37):6131-6143. One
candidate treatment procedure for variceal hemorrhage is the
transjugular intrahepatic portosystemic shunt (TIPS) procedure
discussed in Loffroy. However, Loffroy reports that the TIPS
procedure can be associated with troubling outcomes such as stent
displacement, 10 to 29% relapse rates, or cardiac failure.
SUMMARY
[0004] The invention provides methods and devices for creating a
shunt (that is, a new passage) from a portal vein of a patient to a
hepatic vein using a device with intravascular imaging capabilities
and blood pressure measurement capabilities. The integration of
intravascular imaging in a catheter with a needle for creating the
shunt aids in the precise placement of the shunt between the portal
vein and the hepatic vein. The integration of a pressure sensor
helps determine the successful creation of a shunt for the relief
of portal hypertension. The newly-formed shunt allows blood flow to
bypass the liver, and the shunt may be expanded or preserved using
a balloon, stent, or both. The use of an intravascular imaging
device on the catheter that carries the needle to the shunt site
gives a practitioner three-dimensional information about a spatial
relationship between the portal vein and the hepatic vein--where
prior art procedures had only two-dimensional angiography
information--allowing the practitioner to use the needle to
precisely and accurately pierce through the tissue and create the
shunt. Additionally, the catheter or a lumen through needle which
extends from the catheter may be used to place a guidewire into the
shunt, allowing a balloon and/or stent to be delivered to the
shunt. Since the shunt was created using the 3D guidance provided
by intravascular imaging on the shunt-creation device, the shunt
and any balloon or stent is located correctly in a time-effective
manner. Since the shunt is timely placed in the correct location,
it may successfully relieve portal hypertension and avoid variceal
hemorrhage. Thus treatment using devices and methods of the
invention may relieve symptoms and decrease the mortality rates of
cirrhosis, portal hypertension, or variceal hemorrhage.
[0005] In certain aspects, the invention provides a method of
creating an intrahepatic portosystemic shunt. The method includes
directing a catheter down a jugular vein and into a hepatic vein of
a patient, operating an imaging device such as an ultrasound
transducer disposed on the catheter from within the hepatic vein to
obtain an image of a portal vein of the patient, and extending a
needle member out from within the catheter to create a shunt
defining a passageway through which blood can flow from the portal
vein to the hepatic vein. A pressure sensor on the needle member
may be used to verify a change in pressure that indicates
successful creation of the shunt. Preferably, the needle member
extends away from a side of the catheter by a distance of at least
one centimeter. The needle member may be configured to exit from a
port on the catheter and the imaging device may be operable to
capture the image of the portal vein prior to and during the needle
member being extended from the catheter. The method may include
inserting a guidewire through a lumen within the needle member,
removing the needle member from the shunt while leaving the
guidewire within the shunt, and using the guidewire to insert a
balloon catheter comprising a balloon into the shunt. The balloon
may be used to expand a cross-sectional area of the shunt, after
which the balloon catheter is removed from the shunt and a stent is
delivered to the shunt.
[0006] In some embodiments, the catheter comprises a needle exit
port in proximity to the imaging device and the needle--when
extended from the catheter through the needle exit port--assumes a
curved shape and extends a distance away from the needle exit port.
The needle extends from the needle exit port in a direction away
from the catheter (e.g., by a distance of at least about 1 cm). A
distal tip of the needle, when the needle is extended from the
catheter, may define an angle .theta. with the catheter where
.theta. is at least 65.degree. and is preferably at least
75.degree.. In certain embodiments, the needle comprises a shape
memory metal.
[0007] Aspects of the invention provide an apparatus for creating
an intrahepatic portosystemic shunt. The apparatus includes a
catheter with an extended body configured for insertion down a
jugular vein into a hepatic vein of a patient, an intravascular
imaging device (e.g., an IVUS transducer) on a distal portion of
the extended body, a needle exit port on the distal portion of the
extended body, and a needle disposed within a lumen in the catheter
and configured to be pushed out of the exit port and extend away
from a side of the extended body by a distance of at least one
centimeter. The apparatus includes a pressure sensor on the needle.
The needle may include a shape memory metal (e.g., nitinol) that
assumes a curved shape as the needle exits the exit port. In
certain embodiments, the needle has a lumen that is dimensioned to
receive a guidewire extending therethrough.
[0008] Preferably, the needle is dimensioned to extend from the
exit port away from the side of the catheter body through tissue
and into a portal vein. The needle may include a sharp or beveled
tip configured to pierce through the tissue between the hepatic
vein and the portal vein thereby creating a portosystemic shunt.
The needle may include a lumen for delivering a treatment agent
(e.g., a thrombolytic agent) to the tissue.
[0009] The imaging device (e.g., IVUS transducer) may be operable
to produce an image of the portal vein when within the hepatic
vein. A proximal end of the catheter may be connected to an imaging
system comprising a processor and a display, which can display
images produced by the IVUS transducer.
[0010] The pressure sensor may further include a functional
measurement instrument for measuring fluid velocity. An apparatus
of the invention may be provided with a positioning mechanism, such
as a multi-balloon positioning mechanism that can brace and orient
the needle.
[0011] The invention provides methods and devices for creating a
shunt from a portal vein of a patient to a hepatic vein using a
device with intravascular imaging capabilities and a multi-balloon
positioning mechanism. The integration of intravascular imaging in
a catheter with a needle for creating the shunt aids in the precise
placement of the shunt between the portal vein and the hepatic
vein. The integration of a multi-balloon positioning mechanism
allows for adjustment of position of the shunt-creation needle by
modulating the relative inflation of two (or more) balloons
extending along the body of the device. The use of an intravascular
imaging device on the catheter that carries the needle to the shunt
site gives a practitioner three-dimensional information about a
spatial relationship between the portal vein and the hepatic vein.
The multi-balloon positioning device aids in bracing the catheter
within the hepatic vein, giving the device purchase, thus aiding
the needle in precisely and accurately piercing through the tissue
to create the shunt.
[0012] In some aspects, the invention provides a device for
creating an intrahepatic portosystemic shunt. The device includes a
multi-balloon positioning mechanism. The device has a catheter with
an extended body configured for insertion down a jugular vein into
a hepatic vein of a patient. A distal portion of the extended body
includes an intravascular imaging device, a needle exit port, and a
needle disposed within a lumen in the catheter. The needle is
configured to be pushed out of the exit port and extend away from a
side of the extended body. The device includes a first balloon and
a second balloon disposed in parallel to one another along a length
of the extended body opposed to the needle exit port, wherein
inflation of the first balloon and the second balloon biases a
portion of the extended body towards a side of the hepatic vein.
Preferably, the needle extends away from the side of the extended
body by a distance of at least 1 cm. The needle may include a shape
memory material that assumes a curved shape as the needle exits the
exit port. In certain embodiments, the device includes a pressure
sensor disposed on the needle. The intravascular imaging device may
use an ultrasound transducer to produce an image of a portal vein
when within the hepatic vein.
[0013] Aspects of the invention provide a method of creating an
intrahepatic portosystemic shunt by directing a catheter down a
jugular vein and into a hepatic vein of a patient and operating an
imaging device disposed on the catheter from within the hepatic
vein to obtain an image of a portal vein of the patient. The method
includes inflating at least a first balloon and a second balloon to
position the catheter within the hepatic vein, where the first
balloon and the second balloon disposed on the catheter
substantially opposed to a needle exit port. A needle is extended
out from the needle exit port to create a shunt defining a
passageway through which blood can flow from the portal vein to the
hepatic vein. Preferably, the first balloon and the second balloon
extend along the body of the catheter substantially parallel to one
another and spaced apart from one another and each spaced apart
from the needle exit port along a circumference around the
catheter. The method may include adjusting the orientation of the
needle by adjusting the relative inflation of the first balloon and
the second balloon.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows organs of the human body.
[0015] FIG. 2 depicts elements of the portal venous system.
[0016] FIG. 3 illustrates the liver and a typical hepatic artery as
well as portal vein.
[0017] FIG. 4 depicts an apparatus for creating an intrahepatic
portosystemic shunt.
[0018] FIG. 5 gives a detailed view of a needle 501 extended from a
catheter.
[0019] FIG. 6 illustrates use of apparatus for creating an
intrahepatic portosystemic shunt.
[0020] FIG. 7 diagrams a method for creating an intrahepatic
portosystemic shunt.
[0021] FIG. 8 shows a needle extending from an exit port on a
catheter.
[0022] FIG. 9 illustrates a curved shape of a needle.
[0023] FIG. 10 shows a beveled tip on a needle.
[0024] FIG. 11 diagrams a stent in a shunt.
[0025] FIG. 12 presents a guidewire with a pressure sensor.
[0026] FIG. 13 illustrates a guidewire with a flow sensor.
[0027] FIG. 14 shows a combination sensor tip of a guidewire.
[0028] FIG. 15 shows fine wire conductors of a guide wire.
[0029] FIG. 16 illustrates a system of the invention.
[0030] FIG. 17 depicts a shunt creation apparatus that uses a
positioning mechanism.
[0031] FIG. 18 shows a device 1 with a first balloon and a second
balloon inflated.
[0032] FIG. 19 gives a cross-section view of a device with a
multi-balloon positioning mechanism.
[0033] FIG. 20 illustrates use of the positioning device.
DETAILED DESCRIPTION
[0034] The invention provides a crossing catheter with
intravascular imaging for use in a transjugular intrahepatic
portosystemic shunt (TIPS) procedure and methods for performing a
TIPS procedure using such a catheter. Methods and devices of the
invention may be used to treat a patient with cirrhosis, portal
hypertension, bleeding of esophageal varices and other related
conditions. A device of the invention provides a crossing catheter
with a wire extension, in which the wire can be used to pierce out
of the first vessel and into the second to create new connections
between two blood vessels in the liver. FIGS. 1-3 are included to
illustrate a typical arrangement of a patient's organs and relevant
portions of the portal venous system.
[0035] FIG. 1 shows important organs of the human body 101. A
patient's trachea 105 extends down to lungs 109, located above
liver 117. Heart 113 is between the lungs while the large intestine
127 and small intestines 125 may be found a lower portion of the
torso. The invention includes the insight that three-dimensional
imaging of organ systems depicted here provide improvements to
methods and systems for treating those systems, as proper treatment
is better served by using a three-dimensional representation of
these components that the simplified 2D information provided by
angiography.
[0036] FIG. 2 introduces elements of the portal venous system in
more detail, showing hepatic artery 149, which carries blood from
the liver back to the vena cava and the heart 113. Portal vein 145
carries blood from the intestines and intra-abdominal organs to the
liver 117. For ease of visualization, the figure includes stomach
121, pancreas 161, and the spleen 165. Duodenum 131 connects
stomach 121 to the jejunum 139 of small intestines 125.
[0037] FIG. 3 zooms in on liver 117 and specifically shows a
typical hepatic artery 149 extending to heart 113 as well as portal
vein 145, extending from the spleen 165 and the gastrointestinal
tract. Portal vein 145 is a blood vessel that conducts
nutrient-rich blood from the gastrointestinal tract and spleen to
the liver. Liver 117 processes nutrients in the blood and filters
toxins. The liver receives about 75% of its blood through the
hepatic portal vein, with the remainder coming from the hepatic
artery proper. The blood leaves the liver to the heart in the
hepatic veins. It is noted that portal vein 145 is not a true vein,
as it conducts blood to capillary beds in the liver and not
directly to the heart. Portal vein 145 is usually formed by the
confluence of the superior mesenteric and splenic veins and also
receives blood from the inferior mesenteric, gastric, and cystic
veins. The invention includes the insight that the relationship
between hepatic artery 149 and portal vein 145 is more complex than
can be simply represented in two dimensions. All or any portion of
one may be disposed posterior or anterior to all or any portion of
the other. The invention provides systems and methods that use 3D
intravascular imaging in a TIPS procedure.
[0038] FIG. 4 depicts an apparatus 401 for creating an intrahepatic
portosystemic shunt. Apparatus 401 may be used to create the access
between the two vessels. Apparatus 401 includes a catheter with an
extended body 405 having a distal portion 451 and a proximal
portion 445. Distal portion 451 includes an exit port from which a
needle 501 may extend as well as an imaging device 505. Distal
portion 451 also includes a pressure sensor 404, which may be
mounted on the needle 501 (or elsewhere on the apparatus 401). The
catheter extends from handle 421 and may include a needle
deployment portion 415 having needle depth markers and a locking
needle stop ring. At the base of handle 421 is an access port 427
opening to a needle guide wire lumen. Connected to and extending
from proximal portion 445 is a connector 433 for connection to an
imaging instrument.
[0039] FIG. 5 gives a detailed view of distal portion 451, showing
needle 501 extended from the distal portion 451 of the extended
catheter body 405 with in intravascular imaging device 505 on
extended catheter body 405. In the depicted embodiment,
intravascular imaging device 505 is disposed just distal to a
needle exit port. The needle 501 may have the pressure sensor 404
disposed on a distal portion of the needle. The pressure sensor 404
can be formed of a crystal semiconductor material having a recess
therein and forming a diaphragm bordered by a rim. A reinforcing
member is bonded to the crystal and reinforces the rim of the
crystal and has a cavity therein underlying the diaphragm and
exposed to the diaphragm. A resistor having opposite ends is
carried by the crystal and has a portion thereof overlying a
portion of the diaphragm. Electrical conductor wires can be
connected to opposite ends of the resistor and extend within the
needle 501 to the proximal portion of the apparatus 401. Additional
details of suitable pressure sensors that may be used with devices
of the invention are described in U.S. Pat. No. 6,106,476. Further
discussion of the pressure sensor is given below with respect to
FIG. 12. Device 401 further includes an imaging device 505 to
perform intravascular imaging.
[0040] Any suitable imaging modality may be provided by
intravascular imaging device 505 such as, for example, optical
coherence tomography, optic-acoustical imaging, ultrasound, or any
others. In a preferred embodiment, imaging device 505 operates via
intravascular ultrasound (IVSU).
[0041] The imaging device 505 may use phased-array IVUS device or
rotational IVUS. IVUS imaging provides a tool for assessing tissue
of the human body from within to determine the need for treatment,
to guide an intervention, or to assess its effectiveness. Where
intravascular imaging device 505 uses IVUS, catheter 401 including
one or more IVUS transducer is introduced into the vessel and
guided to the area to be imaged. The transducers emit and then
receive backscattered ultrasonic energy in order to create an image
of the vessel of interest. Ultrasonic waves are partially reflected
by discontinuities arising from tissue structures (such as the
various layers of the vessel wall) and other features of interest.
Echoes from the reflected waves are received by the transducer and
passed along to an IVUS imaging system. The imaging system
processes the received ultrasound echoes to produce a 360-degree,
three-dimensional image of the vessel where the device is placed.
IVUS imaging devices suitable for modification for use with the
invention are described in U.S. Pat. Nos. 4,794,931; 5,000,185;
5,313,949; 5,243,988; 5,353,798; 4,951,677; 4,841,977; 5,373,849;
5,176,141; 5,240,003; 5,375,602; 5,373,845; 5,453,575; 5,368,037;
5,183,048; 5,167,233; 4,917,097; and 5,135,486, each incorporated
by reference.
[0042] There are two general types of IVUS devices in use today:
rotational and solid-state (also known as synthetic aperture phased
array). For a typical rotational IVUS device, a single ultrasound
transducer element is located at the tip of a flexible driveshaft
that spins inside a plastic sheath inserted into the vessel of
interest. The transducer element is oriented such that the
ultrasound beam propagates generally perpendicular to the axis of
catheter 401. A fluid-filled sheath may protect the vessel tissue
from the spinning transducer and driveshaft while permitting
ultrasound signals to propagate from the transducer into the tissue
and back. As the driveshaft rotates, the transducer is periodically
excited with a high voltage pulse to emit a short burst of
ultrasound. The same transducer then listens for the returning
echoes reflected from various tissue structures. The IVUS imaging
system assembles a two dimensional display of the vessel
cross-section from a sequence of pulse/acquisition cycles occurring
during a single revolution of the transducer.
[0043] In contrast, solid-state IVUS devices carry a transducer
complex that includes an array of ultrasound transducers
distributed around the circumference of the device connected to a
set of transducer controllers. The transducer controllers select
transducer sets for transmitting an ultrasound pulse and for
receiving the echo signal. By stepping through a sequence of
transmit and receive sets, the solid-state IVUS system can
synthesize the effect of a mechanically scanned transducer element
but without moving parts. The same transducer elements can be used
to acquire different types of intravascular data. The different
types of intravascular data are acquired based on different manners
of operation of the transducer elements. The solid-state scanner
can be wired directly to the imaging system with a simple
electrical cable and a standard detachable electrical
connector.
[0044] The transducer subassembly can include either a single
transducer or an array. The transducer elements can be used to
acquire different types of intravascular data, such as flow data,
motion data and structural image data. For example, the different
types of intravascular data are acquired based on different manners
of operation of the transducer elements. For example, in a
gray-scale imaging mode, the transducer elements transmit in a
certain sequence one gray-scale IVUS image. Methods for
constructing IVUS images are well-known in the art, and are
described, for example in U.S. Pat. No. 8,187,191; U.S. Pat. No.
7,074,188; U.S. Pat. No. 6,200,268, each incorporated by reference.
The imaging system allows one image (or frame) of flow data to be
acquired. Methods and processes for acquiring different types of
intravascular data, including operation of the transducer elements
in the different modes (e.g., gray-scale imaging mode, flow imaging
mode, etc.) consistent with the present invention are further
described in U.S. Pat. No. 7,914,458 to Hossack; U.S. Pat. No.
7,846,101 to Eberle; U.S. Pat. No. 7,226,417 to Eberle; U.S. Pat.
No. 6,049,958 to Eberle; and U.S. Pat. No. 5,846,205 to Curley,
each incorporated by reference.
[0045] The acquisition of each flow frame of data is interlaced
with an IVUS gray scale frame of data. Operating an IVUS catheter
to acquire flow data and constructing images of that data is
further described in U.S. Pat. No. 5,921,931 to O'Donnell and U.S.
Pub. 2013/0303907 to Corl, each incorporated by reference.
Commercially available software for operating an IVUS catheter in
flow mode and displaying flow data is CHROMAFLOW (IVUS fluid flow
display software offered by the Volcano Corporation).
[0046] In certain embodiments, the imaging device is an OCT device.
OCT systems and methods are generally described in U.S. Pat. No.
8,108,030; U.S. Pat. No. 8,049,900; U.S. Pat. No. 7,929,148; U.S.
Pat. No. 7,853,316; U.S. Pat. No. 7,711,413; U.S. Pub.
2011/0152771; U.S. Pub. 2010/0220334; U.S. Pub. 2009/0043191; U.S.
Pub. 2008/0291463; U.S. Pub. 2008/0180683; U.S. Pub. 2012/0224751;
U.S. Pub. 2012/0136259; U.S. Pub. 2012/0013914; U.S. Pub.
2011/0152771; and U.S. Pub. 2009/0046295, each incorporated by
reference.
[0047] OCT systems of the invention include a light source. The
light source may be any light source generally used with OCT.
Exemplary light sources include a narrow line width tunable laser
source or a superluminescent diode source. Examples of narrow line
width tunable laser sources include, but are not limited to, lasers
having a Bragg diffraction grating or a deformable membrane, lasers
having a spectral dispersion component (e.g., a prism), or
Fabry--Perot based tuning laser.
[0048] OCT systems of the invention also include an interferometer.
The interferometer may be any interferometer generally used with
OCT. Typically, the interferometer will have a differential beam
path for the light or a common beam path for the light. In either
case, the interferometer is operably coupled to the light source.
In a differential beam path layout, light from a broad band light
source or tunable laser source is input into an interferometer with
a portion of light directed to a sample and the other portion
directed to a reference surface. A distal end of an optical fiber
is interfaced with a catheter for interrogation of the target
tissue during a catheterization procedure. The reflected light from
the tissue is recombined with the signal from the reference surface
forming interference fringes (measured by a photovoltaic detector)
allowing precise depth-resolved imaging of the target tissue on a
micron scale. Exemplary differential beam path interferometers are
Mach--Zehnder interferometers and Michelson interferometers.
[0049] The differential beam path optical layout of the
interferometer includes a sample arm and a reference arm. The
sample arm is extends through catheter 401. In the interferometer,
there is a circulator where the emitted light is split to the
sample arm and the reference arm. The system also includes a
circulator that directs light to the sample and receives reflected
light from the sample and directs it toward a detector. The system
also includes a circulator that directs light to the reference
surface and received reflected light from the reference surface and
directs it toward the detector. There is also a circulator at the
point at which reflected light from the sample and reflected light
from the reference are recombined and directed to the detector.
[0050] In a common beam path system, rather than splitting a
portion of the light to a reference arm, all of the produced light
travels through a single optical fiber. Within the single fiber is
a reflecting surface. A portion of the light is reflected off that
surface prior to reaching a target tissue (reference) and a
remaining portion of the light passes through the reflecting
surface and reaches the target tissue. The reflected light from the
tissue recombines with the signal from the reference forming
interference fringes allowing precise depth-resolved imaging of the
target tissue on a micron scale. Common beam path interferometers
are further described in U.S. Pat. No. 7,999,938; U.S. Pat. No.
7,995,210; and U.S. Pat. No. 7,787,127, each incorporated by
reference
[0051] The common beam path optical layout of the interferometer
includes a single array of optical fibers that are connected to a
circulator. The array of optical fibers are configured to
accommodate and couple to a catheter. The circulator directs light
transmitted from the light source through the array of optical
fibers of the common beam path optical layout to a sample and
reference, and receives the reflected light from the sample and
reference and directs it to the detector.
[0052] OCT systems of the invention include a detector. The
detector includes photodetection electronics that may include for
example photodiodes to convert light to electronic impulses and a
chip such as a field programmable gate array to convert the
electronic impulses into computer-readable 3D image data. OCT
systems of the invention may conduct any form of OCT known in the
art. One manner for conducting OCT may be Swept-Source OCT
("SS-OCT"). SS-OCT time-encodes the wavenumber (or optical
frequency) by rapidly tuning a narrowband light source over a broad
optical bandwidth. The high speed tunable laser sources for SS-OCT
exhibit a nonlinear or non-uniform wavenumber vs. time [k(t)]
characteristic. As such, SS-OCT interferograms sampled uniformly in
time [S(t), e.g., using an internal digitizer clock] must be
remapped to S(k) before Fourier transforming into the path length
(z) domain used to generate the OCT image.
[0053] Other imaging modalities that may be provided by
intravascular imaging device 505 may include spectroscopic devices,
(including fluorescence, absorption, scattering, and Raman
spectroscopies), Forward-Looking IVUS (FLIVUS), high intensity
focused ultrasound (HIFU), radiofrequency, optical light-based
imaging, magnetic resonance, radiography, nuclear imaging,
photoacoustic imaging, electrical impedance tomography, or others.
As discussed above, by including intravascular 3D imaging on a
device for creating an intrahepatic shunt, the ability to create a
shunt quickly and correctly may be improved as a practitioner may
view a 3D image of the portal vein from the hepatic vein on a
monitor while guiding needle 501 from the hepatic vein to the
portal vein.
[0054] FIG. 6 illustrates use of apparatus 401 in a method of
creating an intrahepatic portosystemic shunt 607. With FIG. 6 for
references, after entry into the internal jugular vein, catheter
401 is introduced and guided through the superior vena cava and
into a hepatic vein according to methods of the invention.
[0055] FIG. 7 diagrams steps of a method 801 for creating an
intrahepatic portosystemic shunt 607. In method 801, a guidewire
may be inserted 805 down the jugular vein of patient 101 from the
neck (optionally using X-ray guidance to complement the
intravascular imaging). Intravascular imaging device 505 is
operated 809 to obtain a 3D image of the tissue, aiding the
practitioner in viewing portal vein 145 from hepatic vein 149.
Needle 501 is extended from apparatus 401 and used to cross 817 the
tissue between portal vein 145 and hepatic vein 149, thus creating
shunt 607. Pressure sensor 404 can be used to measure 819 pressure
and the measure of pressure may show successful creation of the
shunt. Needle 501 is extended from catheter 401 and used to
puncture the liver from a central portion of hepatic vein 149 and
enter the main portal branch, usually the right portal vein 145. An
important advantage in using apparatus 401 lies within its
intravascular imaging capabilities. A practitioner can place
apparatus 401 in the first vessel, see the second vessel using IVUS
(the sound waves can travel through the liver tissue to permit
visualization of the second vessel), and then use the needle member
501 to create the inter-vessel access. It is noted that use of
intravascular imaging on device 401 aids in avoiding laceration of
the liver capsule with needle 501 or entering the hepatic artery.
Intravascular imaging is useful in making the TIPS tract
intraparenchymal, or dilatation of the extrahepatic portion of the
portal vein could result in undesirable exsanguination. Use of the
invention may reduce the use of fluoro and reduce the overall
procedure time. Once the shunt is created, catheter 401 is
exchanged 821 over a guidewire for a catheter to deliver a balloon,
stent, or both, and a stent may be placed 827 in the shunt.
[0056] FIG. 8 shows needle 501 extending from an exit port on a
side of distal portion 451 of catheter 401. Also shown in FIG. 8 is
guidewire 801 over which catheter 401 may be advanced, or which may
be advanced through catheter 401. It is noted that intravascular
imaging sensor 505--which may include an ultrasound transducer--is
depicted as being disposed just distal to the exit port, although
it can be located in other places. Needle 501 includes pressure
sensor 404. FIG. 8 illustrates that a dimension of needle 501
provides a lateral reach (LR) of at least 1 cm. This allows needle
501 to reach portal vein 145. In the portal vein, needle 501 can be
advanced to create the shunt. In certain embodiments, device 401
includes a needle 501 that provides a lateral reach of at least
about 1.5 cm and it may be 2 cm or greater. To aid in creating the
shunt, needle 501 should preferably extend substantially oblique to
the body of catheter 401.
[0057] FIG. 9 illustrates a curved shape of needle 501 that defines
an angle of about 79.degree. with an axis of catheter 401 and also
defines a lateral reach of at least about 0.39 inches or about 1
cm. Needle 501 preferably includes a shape-memory metal such as
nitinol such that needle 501 is maintained with a shape of catheter
401 when needle 501 is retained within catheter 401, but so that
needle 501 assumes a curved shape as illustrated in FIG. 9 when
extended from catheter 401. To aid in piercing through the liver
tissue, needle 501 preferably includes a sharpened or beveled tip
901.
[0058] FIG. 10 illustrates beveled tip 901 on needle 501. With
reference back to FIG. 9, it will be appreciated that beveled tip
901 when needle 501 is extended can define an angle .theta. with an
axis of catheter 401 and a proximal portion of needle 501. For
effective creation of shunt 607, angle .theta. is preferably
greater than about 55.degree. and more preferably at least
75.degree. or more. In the depicted embodiment, angle .theta. is
about 79.degree.. Once needle 501 has created shunt 607, apparatus
401 may be exchanged 821 with a catheter for delivering a balloon,
stent, or both. The needle tract may then be dilated by a balloon
catheter, establishing a connection between the portal and systemic
circulation directly inside the liver parenchyma. The parenchymal
tract may be kept open by insertion of a stent. See
Hernandez-Guerra, 2004, PTFE-covered stents improve patency in
Budd-Chiari syndrome, Hepatology 40:1197-1202.
[0059] FIG. 11 illustrates stent 1109 in shunt 607. The dotted line
represents the path defined by the guidewire and the path followed
by imaging/shunt creation catheter 401 as well as a stent delivery
catheter or balloon catheter, and those devices are not drawn in
FIG. 11 Stent 1109 preferably defines a generally cylindrical
shape. A PTFE-covered stent may be used, a bare metal stent, or any
other suitable stent. By alternate separation of the intersecting
points of the lattice, a flexibility of the axis of shunt stent
1109 is achieved, so that it also can be used in a curved shunt. An
uncovered part of stent 1109 about 2 cm long may protrude into the
portal vein 145 to anchor stent 1109 and aid blood flow. The shunt
diameter may be finalized by balloon dilatation of stent 1109.
Stent 1109 diverts portal blood into systemic circulation,
resulting in the decompression of portal hypertension. The size of
the balloon catheter is usually 8 mm. In certain embodiments,
device 401 or a guidewire that has been extended through the
catheter includes a functional measurement sensor to measure
pressure, velocity, or both.
[0060] In some embodiments, a pressure sensor (or a flow velocity
sensor, or a combination sensor) is additionally or alternatively
placed on a catheter of the device or a guidewire for use in
methods, devices, and kits of the invention.
[0061] FIG. 12 illustrates a guidewire 1201 with a pressure sensor
1204. Guidewire 1201 generally defines an elongated body extending
from a proximal end 1210 to a distal end 1202. Proximal end 1210
connects to connector housing 1215, which offers a modular plug 221
for connection to a computing device in systems of the
invention.
[0062] A pressure sensor allows one to obtain pressure measurements
within a body lumen. A particular benefit of pressure sensors is
that pressure sensors allow one to measure of fractional flow
reserve (FFR) in vessel, which is a comparison of the pressure
within a vessel at positions on either side of the shunt. The level
of FFR determines the patency of the shunt.
[0063] Pressure sensor 1204 can be mounted on the distal portion of
a flexible elongate member. In certain embodiments, the pressure
sensor is positioned distal to the compressible and bendable coil
segment of the elongate member. This allows the pressure sensor to
move away from the longitudinal axis and coil segment as bended.
The pressure sensor can be formed of a crystal semiconductor
material having a recess therein and forming a diaphragm bordered
by a rim. A reinforcing member is bonded to the crystal and
reinforces the rim of the crystal and has a cavity therein
underlying the diaphragm and exposed to the diaphragm. A resistor
having opposite ends is carried by the crystal and has a portion
thereof overlying a portion of the diaphragm. Electrical conductor
wires can be connected to opposite ends of the resistor and extend
within the flexible elongate member to the proximal portion of the
flexible elongate member. Additional details of suitable pressure
sensors that may be used with devices of the invention are
described in U.S. Pat. No. 6,106,476, which describes suitable
methods for mounting the pressure sensor 1404 within a sensor
housing. As discussed above, additionally or alternatively, a
guidewire can include a flow sensor. In some embodiments, a
guidewire is used that includes a flow sensor. A suitable product
for guidewire 1201 is the PrimeWire PRESTIGE from Volcano
Corporation. Preferably the guidewire includes of a flexible
elongate element having proximal and distal ends and a diameter of
0.018'' or less as disclosed in U.S. Pat. No. 5,125,137, U.S. Pat.
No. 5,163,445, U.S. Pat. No. 5,174,295, U.S. Pat. No. 5,178,159,
U.S. Pat. No. 5,226,421, U.S. Pat. No. 5,240,437 and U.S. Pat. No.
6,106,476, each incorporated by reference.
[0064] A guidewire of the invention may include a flexible elongate
element having proximal and distal extremities, and can be formed
of a suitable material such as stainless steel, Nitinol, polyimide,
PEEK or other metallic or polymeric materials having an outside
diameter for example of 0.018'' or less and having a suitable wall
thickness, such as, e.g., 0.001'' to 0.002''. This flexible
elongate element is conventionally called a hypotube. In one
embodiment, the hypotube may have a length of less than 120 cm,
preferably about 50, 150, 70, or 80 cm. Typically, such a guide
wire may further include a stainless steel core wire extending from
the proximal extremity to the distal extremity of the flexible
elongate element to provide the desired torsional properties to
facilitate steering of the guide wire in the vessel and to provide
strength to the guidewire and prevent kinking. The guidewire can
have a diameter of about 0.014'' (0.35 mm) and can include the
functional instrumentation of the Doppler guide wire sold under the
name FLOWIRE by Volcano Corporation, the pressure guidewire sold
under the name PRIMEWIRE PRESTIGE by Volcano Corporation, or
both.
[0065] Guidewire 1201 with a pressure sensor 1204 may be used to
measure pressure and thus a pressure gradient may be measured.
Depending on the pressure gradient measured between the portal vein
and right atrium after stent or stent graft placement, a larger
angioplasty balloon catheter may be used for stepwise
decompression. Guidewire 1201 measures blood pressure after the
procedure within the main portal vein. Once the value is stabilized
and recorded, pressure sensor 1204 is moved to the hepatic vein or
the suprahepatic inferior vena cava, and the blood pressure is
again recorded. This can provide pressure values in the portal vein
and hepatic vein before and after shunt placement to aid in
evaluating the procedure.
[0066] Additionally or alternatively, blood flow velocity may be
measured using a guidewire with a functional measurement
sensor.
[0067] FIG. 13 illustrates a guidewire 1201 with a flow sensor
1305. The flow sensor can be used to measure blood flow velocity
within the vessel, which can be used to assess coronary flow
reserve (CFR), or similar. The flow sensor can be, for example, an
ultrasound transducer, a Doppler flow sensor or any other suitable
flow sensor, disposed at or in close proximity to the distal tip of
the guidewire. The ultrasound transducer may be any suitable
transducer, and may be mounted in the distal end using any
conventional method, including the manner described in U.S. Pat.
Nos. 5,125,137, 6,551,250 and 5,873,835. A suitable product for
guidewire 1201 with a flow sensor 1305 is the FLOWIRE from Volcano
Corporation.
[0068] In a preferred embodiment, methods of the invention employ a
guidewire that includes a device for measuring pressure and a
device for measuring flow, i.e., a combination tip.
[0069] FIG. 14 shows a combination sensor tip 1400 of a guidewire
1201 according to embodiments of the present invention. The
combination sensor tip 1400 includes a pressure sensor 1404 within
sensor housing 1403, and optionally includes a radiopaque tip coil
1405 distal to proximal coil 1406. Combination sensor tip includes
an ultrasound transducer 1409 disposed therein. The ultrasound
transducer 1409 may be any suitable transducer, and may be mounted
in the distal end using any conventional method, including the
manner described in U.S. Pat. No. 5,125,137, which is fully
incorporated herein by reference. Conductors (not shown) may be
secured to the front and rear sides of the ultrasound transducer
1409, and the conductors may extend interiorly to the proximal
extremity of a guide wire.
[0070] The combination sensor tip 1400 also includes a pressure
sensor 1404 in close proximity to the distal end 1202 of the
combination sensor tip 1400. The pressure sensor 1404 may be of the
type described above. The combination sensor tip 1400 is
advantageous because by having both the ultrasound transducer 1409
and the pressure sensor 1404 near its distal end, the combination
sensor tip 1400 is capable of being positioned distally beyond the
shunt. Additionally, the combination sensor tip 1400 is able to
take measurements from the ultrasound transducer 1409 and the
pressure 104 at approximately the same location and approximately
the same time. Constructions suitable for use with a guidewire of
the invention are discussed in U.S. Pub. 2013/0030303 to Ahmed, the
contents of which are incorporated by reference.
[0071] FIG. 15 shows fine wire conductors 1507 passing through the
guide wire to conductive bands 1508 near the proximal end 1210 of
the guide wire. Signals from the ultrasound transducer 1409 and the
pressure sensor 1404 may be carried by conductors 1507. Usually
three electrical connectors are necessary for a stand-alone
pressure measurement guidewire and two electrical connectors are
necessary for a stand-alone flow measurement guidewire. A guide
wire incorporating the combination sensor tip 1400 of the present
invention includes electrical conductors 1507 extending through the
lumen of the guidewire and conductive bands 1508 on the proximal
end of the guidewire. The conductive bands 1508 may be electrically
isolated from each other by means of epoxy 1509. Alternatively,
polyimide tubes may be used to isolate conductors from the
conductive bands.
[0072] The electrical connection wires can include a conductive
core made from a conductive material, such as copper, and an
insulating coating, such as a polyimide, Fluoro-polymer, or other
insulating material. The electrical connection wires extend from
one or more sensors located on the distal end of the guidewire, run
down the length of the guidewire, and connect to a connector
housing at a proximal end.
[0073] Any suitable arrangement of the electrical connection wires
through the length of the elongate member can be used. The
arrangement of electrical connection wires provides for a stable
connection from the proximal end to the distal end of the
guidewire. Preferably, proximal end 1210 connects to connector
housing 1215 as shown in FIG. 12. In certain embodiments, the
electrical connector wires are joined together to form a male
connector at a proximal end. The male connector mates with a female
connector of the connector housing. The termination of the male
connector can be performed by a metal deposition process as
described in U.S. Pat. No. 6,210,339, incorporated herein by
reference in its entirety. The deposited metal (or any conductive
material) permanently adheres or couples to the exposed conductive
wires at points where the polyimide layers were removed. After the
masking material is removed, there are independent conductive
stripes, each connected to a different respective electric wire.
Because of the precision nature of the winding process as well as
the masking and metal deposition processes, a male connector is
made that is short in length, yet very reliable, in mating with a
female connector and cable. Alternatively, conductive bands may be
coupled to the exposed ends of the electric wires instead of the
metallizing process.
[0074] The connector housing can be connected to an instrument,
such as a computing device (e.g. a laptop, desktop, or tablet
computer) or a physiology monitor, that converts the signals
received by the sensors into pressure and velocity readings in
systems of the invention.
[0075] As discussed above, methods and devices of the invention may
include one or any combination of intravascular imaging sensor 505,
pressure sensor 1204, flow sensor 1305, or combination sensor tip
1400. Data collected from such devices may be received at an
imaging instrument, computer system, or both.
[0076] FIG. 16 illustrates a system 1601 of the invention. System
1601 includes catheter 401 and intravascular imaging base station
1631 to receive intravascular imaging data from imaging device 505.
Base station 1631 may include, for example, a field-programmable
gate array to convert the raw incoming data into files for analysis
by computer 1625. System 1601 optionally includes an instrumented
guidewire 1201 operably coupled to a computer device 1625 via
functional measurement base station 1637 (which can be integrated
into base station 1631). Guidewire 1201 includes at least one
sensor such as a pressure sensor or flow sensor as discussed above.
Guidewire 1201 may include a plurality of sensor such as a pressure
sensor and a flow sensor as discussed above. Computer 1625 can be a
dedicated medical imaging instrument, a standard desktop, laptop,
or tablet computer, or a combination thereof (e.g., a medical
imaging instrument with a base station and a laptop or desktop
computer attached to provide a workstation and interface for a
physician.
[0077] In some embodiments, a user interacts with a visual
interface (e.g., a monitor as I/P of computer 1625) to view images
from the imaging system to see the portal vein in 3D and guide
needle 501 thereto. For functional measurement guidewire 1201,
electrical signals are relayed from the conductors via a mating
connector (or contact housing as described herein with respect to a
connector of the present invention) to base station 1637 that
converts the signals into pressure and velocity readings that are
displayed to the user. In addition algorithms such as Coronary Flow
Reserve (CFR) or Fractional Flow Reserve (FFR) may be
calculated.
[0078] System 1601 may include one or a plurality of computers. For
example, system 1601 may include bed-side workstation computer
1625, a connected computer 1619 (e.g., in a control room), or both
and system 1601 may additionally include a server computer 1613 for
processing measurements. A computer in system 1601 such as computer
1625 or connected computer 1619 generally includes a processor
coupled to memory and one or more input/output devices. Computer
1625 or 1619 may be provided by a desktop computer, laptop, tablet,
mobile device, or purpose-built machine (such as a bed-side control
station for a medical imaging system).
[0079] A processor generally refers to a computer microchip such as
the processor sold under the trademark CORE 17 by Intel (Santa
Clara, Calif.).
[0080] Memory generally includes one or more devices for random
access, storage, or both. Preferably, memory includes a tangible,
non-transitory computer readable medium, and may be provided by one
or more of a solid state drive (SSD), a magnetic disc drive (aka,
"a hard drive"), flash memory, an optical drive, others, or a
combination thereof.
[0081] An I/O device may include one or more of a monitor,
keyboard, mouse, touchscreen, Wi-Fi card, cell antenna, Ethernet
port, USB port, light, accelerometer, speaker, microphone, drive
for removable disc, others, or a combination thereof. Preferably,
any combination of computer in system 1601 may communicate through
the use of a network, which may include communication devices for
internet communication, telephonic communication, others, or a
combination thereof.
[0082] Other aspects of the invention include a device with one or
more balloons or other elements for positioning, centering, or
stabilizing the device.
[0083] FIG. 17 depicts an apparatus 1701 for creating an
intrahepatic portosystemic shunt. Apparatus 1701 may be used to
create the access between the two vessels. Apparatus 1701 includes
a catheter with an extended body 1705 having a distal portion 1751
and a proximal portion 1745. The catheter extends from handle 1721
and may include a needle deployment portion 1715 having needle
depth markers and a locking needle stop ring. At the base of handle
1721 is an access port 1727 with openings to a needle guide wire
lumen and one or more inflation lumens. Connected to and extending
from proximal portion 1745 is a connector 1733 for connection to an
imaging instrument. Needle 1725 can be seen extended from needle
exit port 1723. Apparatus 1701 further includes a first balloon
1751 and a second balloon 1753 disposed FIG. 17 shows needle 1725
extending from an exit port 1723 on a side of distal portion 1751
of catheter 1701. Device 1701 includes intravascular imaging sensor
1707--which may include an ultrasound transducer--e.g., disposed
just distal to the exit port 1723, although it can be located in
other places. Needle 1725 preferably provides a lateral reach (LR)
of at least 1 cm. This allows needle 1725 to reach portal vein 145.
First balloon 1751 and a second balloon 1753 provide beneficial
stabilizing functionality to aid in effective creation of an
intrahepatic shunt.
[0084] FIG. 18 shows device 1701 with first balloon 1751 and a
second balloon 1753 inflated and needle 1725 deployed. Device 1701
may have the balloons inflated and the needle extended when
deployed within hepatic vein 149. Imaging sensor 1707 can view
portal vein, aiding a practitioner in creating a shunt. In certain
embodiments, sensor 1707 includes one or more IVUS transducers for
taking intravascular images via ultrasound.
[0085] FIG. 19 gives a cross-section view of device 1701 showing a
first inflation lumen 1907 for inflating first balloon 1751, second
inflation lumen 1913 for inflating second balloon 1753, and needle
lumen 1901, which lumens extend through the catheter of device
1701. The arrangement of first balloon 1751 and a second balloon
1753 as depicted in FIGS. 18 & 19 provides a useful tool for
aiding in a TIPS procedure. The balloons can be used to brace the
device 1701 against the wall of the hepatic vein 149. Needle 1725
is extended from apparatus 1701 and used to cross the tissue
between portal vein 145 and hepatic vein 149, thus creating a
shunt. The needle 1725 is extended from catheter device 1701 and
used to puncture the liver from a central portion of the hepatic
vein 149 while first balloon 1751 and a second balloon 1753 brace
the device 1701 therein.
[0086] One benefit of including a first balloon 1751 and a second
balloon 1753 as depicted in FIG. 19 and FIG. 20 is that a
practitioner may modulate the relative inflation of the two
balloons to adjust the positioning of the needle 1725. Using FIGS.
19 and 20 for reference, if the inflation of first balloon 1751 is
decreased by, for example, 20% while the inflation of the second
balloon is increased by 20%, the change in inflation of the two
balloons will bias the orientation of the needle 1725 in a
clockwise direction (according to the depiction of FIGS. 19 and
20). It will be appreciated that the relative inflation of the two
balloons can be controlled to any desired amount to bias the needle
in either direction or to give additional support to the needle on
one side versus the other where anatomical context demands.
[0087] Thus it can be seen that in some embodiments, the invention
provides a method of creating an intrahepatic portosystemic shunt
that includes directing a catheter 1701 down a jugular vein and
into a hepatic vein 149 of a patient and operating an imaging
device 1707 disposed on the catheter from within the hepatic vein
to obtain an image of a portal vein of the patient. A first balloon
1751 disposed on catheter 1701 in a location substantially opposed
to a needle exit port 1723 may be inflated to aid in bracing the
needle 1725 for penetration of the hepatic tissue or to orient the
needle 1725. A second balloon 1753 disposed on catheter 1701 in a
location substantially opposed to a needle exit port 1723 and the
first balloon 1751 may be inflated to aid in bracing the needle
1725 for penetration of the hepatic tissue or to orient the needle
1725. The method further includes extending the needle 1725 out
from the needle lumen 1901 within the catheter 1701 to create a
shunt defining a passageway through which blood can flow from the
portal vein to the hepatic vein. In a preferred embodiment, the
first balloon 1751 and the second balloon 1753 extend along the
body of catheter 1701 substantially parallel to one another and
spaced apart from one another and each spaced apart from the needle
exit port 1723 (i.e., all spaced about equidistant apart along a
circumference around the catheter 1701). The practitioner may view
an image of the portal vein while adjusting the orientation of the
needle 1725 by adjusting the relative inflation of the balloons.
The invention further includes methods and devices that use other
features and combinations of features discussed herein.
[0088] In certain aspects and embodiments, the invention provides a
kit for a TIPS procedure. The kit includes a guidewire 1201 with a
functional measurement sensor and a catheter apparatus 401 having a
needle 501 disposed therein. Catheter 401 includes an intravascular
imaging device such as an IVUS transducer on a distal portion of
the extended body with a needle exit port also on the distal
portion of the extended body. Needle 501 is disposed within a lumen
in the catheter and configured to be pushed out of the exit port
and extend away from a side of the extended body by a distance of
at least one centimeter. Needle 501 can be removed from catheter
401 and guidewire 1201 may be advanced through catheter 401 to aid
in delivery of a stent 1109. A pressure sensor 1204 (or optionally
a flow sensor 1305 or combination sensor tip 1400) may be used to
measure pressure, flow velocity, or both in shunt 607. The kit is
well suited for creation of portosystemic shunts as discussed
herein. Aspects of the invention may provide a kit that includes
catheter 401 and stent 1109. Useful background may be found in U.S.
Pat. No. 7,729,738 to Flaherty (e.g., columns 17-18); U.S. Pat. No.
8,632,468 to Glossop; and U.S. Pat. No. 8,346,344 to Pfister, the
contents of each of which are incorporated by reference for all
purposes.
[0089] Additional features that may be included in a device of the
invention include one or more of a centering mechanism, an extended
or beveled needle, an aspiration catheter, a lumen for delivery of
an agent, virtual histology functionality provided by a computer
system, virtual biopsy functionality, an ablation mechanism on a
catheter, devices for embolization of endoleaks, or any combination
thereof. Devices and methods of the invention may find use in other
procedures (e.g., portal vein thrombosis, portal vein
hypertension).
[0090] A centering mechanism may include a balloon, struts, a
trough, or other mechanism to stabilize the device so that it can
accurately image and access the second vessel. Centering mechanisms
that may be suitable for modification use with the invention are
discussed in Volcano Corporation's U.S. patent application Ser. No.
14/201,070, filed Mar. 7, 2014.
[0091] Needle 501 is depicted in FIG. 9 has having beveled tip 901,
shown in greater detail in FIG. 10. It is noted that tip 901 may be
extended, beveled, or elongated, i.e., to an extent not depicted in
FIG. 10, to increase lateral reach (e.g., to LR.gtoreq.2 cm or 2.5
cm).
[0092] Device 401 may include a lumen to provide an aspiration
catheter or needle 501 may include a lumen to serve a lytic
delivery/aspiration catheter for thrombosis in the liver. Thus
device 401 or needle 501 could be used to deliver an agent such as
a lytic agent.
[0093] System 1601 may include virtual histology functionality
provided by a computer system that receives data from intravascular
imaging sensor 505, pressure sensor 1204, flow sensor 1305, or
combination sensor tip 1400. A window in needle may be used to
determine tissue coefficient. System 1601 may provide virtual
biopsy functionality (e.g., for cancer detection). Virtual
histology is discussed in Volcano Corporation's patent application
Ser. No. 14/106,260, filed Dec. 13, 2013, and see also U.S. Pub.
2014/0100440
[0094] Device 401 may include an ablation mechanism on a catheter.
For example, a distal end of the catheter may include an electrode
coupled to an RF generator. The generator delivers RF energy to the
electrode to ablate occluding material in the vessel. The electrode
may have a variety of tip shapes including concave, roughened, or
expandable configurations, depending on the size of the vessel and
composition of the occluding material. See U.S. Pat. No. 6,638,222
to Chandrasekaran; U.S. Pat. No. 5,385,148 to Jackson; and U.S.
Pat. No. 8,480,593 to Magnin.
[0095] As discussed herein, the invention provides methods,
devices, and kits that may be used for treatment of cirrhosis or
conditions such as portal hypertension or variceal bleeding.
Additional information may be found in Perz et al., 2006, The
contributions of hepatitis B virus and hepatitis C virus infections
to cirrhosis and primary liver cancer worldwide, J. Hepatol
45(4):529-38; Yin et al., 2013, the surgical treatment for portal
hypertension: a systematic review and meta-analysis, ISRN
Gastroenterology article ID 464053; and Jalan et al., 2000, TIPSS
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NCORPORATION BY REFERENCE
[0096] References and citations to other documents, such as
patents, patent applications, patent publications, journals, books,
papers, web contents, have been made throughout this disclosure.
All such documents are hereby incorporated herein by reference in
their entirety for all purposes.
Equivalents
[0097] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The foregoing embodiments are therefore to be considered
in all respects illustrative rather than limiting on the invention
described herein. Scope of the invention is thus indicated by the
appended claims rather than by the foregoing description, and all
changes which come within the meaning and range of equivalency of
the claims are therefore intended to be embraced therein.
* * * * *